Electrical connector strip having laterally displaced strip feeding edges



Nov. 17, 1953 Q. BERG 2,659,871

' ELECTRICAL CONNECTOR STRIP HAVING LATERALLY DISPLACED STRIP FEEDING EDGES Filed Oct. 5, 1949 2 Sheets-Sheet l /6 I T'ICAn flaw. /6 q I, r /7 /6 @11 wi l MI 1 ATM M 5% 5 INVENTOR. pain/Wm 554%.

{4 BY Z6 43 f- ATTORNEYS:

Nov. 17, 1953 Q. BERG ,8 1

ELECTRICAL CONNECTOR STRIP HAVING LATERALLY DISPLACED STRIP FEEDING EDGES Filed Oct. 3, 1949 2 Sheets-Sheet 2 INVENTORI Quin 77m 552 ATTO RN EYS Patented Nov. 17, 1953 ELECTRICAL CONNECTOR STRIP HAVING LATERALLY DISPLACED STRIP FEEDING EDGES Quentin Berg, New Cumberland, Pa., assignor to Aircraft Mai-ine Products Inc., Harrisburg, Pa.

Application October 3, 1949, Serial No. 119,220

4 Claims.

This invention relates to electrical connectors and the like, and to bonding blanks and multiple blank strips adapted for making electrical connections, leads, and otherelectrical circuit devices, and to methods of application.

In the manufacture and application of electrical connectors it has been customary to form a connector tongue, pin or receptacle, or the like by stamping and, adjacent to it and integral to a ferrule portion, closed into a cylinder, or in open channel form with upturned cars, which can be crimped down onto the wire as a gripping ferrule. These units follow one another in integral succession along the continuous strip, with the ferrule portion of each (or in some few designs the connector tongue, etc.) standing above the adjacent portions thus giving a projecting edge against which a pawl or other feeding device may engage for accurate feeding and positioning of the blanks in an applicator die.

Prior to this invention, there had also been used a connector strip in which the ferrule-forming ears succeeded each other directly along the sides of the strip. In such strip, gaps are punched out between the successive ears to give such feeding edges and to facilitate severance. Such a strip is disclosed in the copending application of Frank L. Pierce Serial No. 7,547 filed February 11, 1948.

The present invention provides for an economy of material and a simplification of the connector strip, without loss of utility. In its broader aspect the invention is applicable to various kinds of connectors, including particularly banding connectors for connecting wires to other conductors; and in one specific aspect it'relates particularly to end contacts, e. -g., for use in lamp sockets.

The present invention provides an improved blank and connector strip from which such lamp contact terminals can be made.,'to an improved contact terminal for lamp sockets and other uses, and to improved methods of construction and assembly.

In accordance with the invention, the terminals can be fabricated from a flat strip of sheet metal, all of which can be usefully incorporated into the assembled terminals, thereby eliminating waste material, simplifying the fabrication and assembly, and reducing the cost of the terminals. Moreover, provision is made so that the electric connection can be at least in part completed directly between the wire, around which the terminal is crimped, and an abutting contact surface, so that good electrical contact can be made.

In the preferred embodiment of the invention a fiat sheet of metal is formed, by bending and cutting, into a channel-like continuous strip of connectors adapted for use in automatic applicators in which they are assembled on a wire, etc. and crimped. The channel-like terminal strip is provided with a series of opposed regularly spaced transverse slits across the upwardly extending sides of the channel, at least a part of. the sides adjacent the slits being bent outwardly to form projecting lateral edges. In the case of the end contact connector these bent out portions are slit from the base and constitute opposed fins spaced along the sides of the channel.

An individual terminal is assembled by severingthe base of the strip between the opposed slits leaving a structure having a short U-shaped channel with the two opposed fins extending outwardly in opposite directions from adjacent ends of the two sides of the channel and a tongue which ordinarily at the instant of severing still projects beyond the fins in the plane of the channel base, but is bent downward into approximately co-planar relation with them, by the action of the applicator. Before or after the severing, the wire conductor is placed in the channel with one of its ends adjacent, or extending slightly beyond, the two fins; the terminal is then crimped to the wire by curling the sides of the channel inwardly over the wire and pressing their edges, which preferably are sharpened,

end-wise down into or against the conductor.

At the same time the forwardly-extending tongue may be bent down to form an additional fin in the same plane as the first-mentioned fins. By the crimping operation, the sides of the channel are bent inward bringing together the upperinside corners of the lateral fins so that, from an end view, the assembled terminal has the appear ance of a block Y, formed by the three fins, with the end of the wire conductor positioned at its center. If desired this conductor can project above the surfaces of the fins so as to make direct contact with a lamp base or other conductive member pressed against it. By utilizing such direct contact it is unnecessary to get contact between the connector and the conductor; it may be applied to an insulated wire without piercing the insulation.

The terminal is secured firmly to the wire conductor by the crimping operation, thus eliminating expensive soldering operations. The three fins provide a relatively large contact area, in a. plane substantially perpendicular to the longitudinal axis of the terminal, against which a removable pressure contact can be maintained, as by the center contact of an electric lamp.

Accordingly, it is a specific object of this invention to provide an improved terminal having particular utility as the center contact in an electric lamp socket, but which is also useful in other applications where electric contact is to be made by abutment of conducting surfaces. It is also an object to provide an improved terminal strip from which such terminals can be readily assembled. Still other aspects of the invention relate to methods of making such strips and terminals, and to apparatus and methods for reducing the cost, improving the quality of the electrical connection, and increasing the speed of fabrication and assembly.

These and other aspects, objects, and advantages of the invention will be in part pointed out in and in part apparent from the following description considered in conjunction with the accompanying drawings, in which similar parts bear similar reference numerals throughout the several views:

Figure 1 is a perspective view of a strip of terminals embodying the invention, and of a single terminal blank severed therefrom;

Figure 2 is a plan view of the connector strip shown in Figure 1;

Figure 3 is a sectional view taken along line H of Figure 2;

Figure 4 is a sectional view taken along line l-J of Figure 3;

Figure 5 is a diagrammatic showing of a flat strip of metal for fabricating the terminal strip of Figures 1, 2 and 3, with solid lines indicating places where slits are to be made and the broken lines indicating lines of bending.

Figure 6 is an end view of a wire conductor and a terminal assembled ready for crimping;

Figure '7 is an end view similar to Figure 6 showing the wire and terminal after crimping;

Figure 8 is an enlarged perspective view showing the assembled terminal;

Figure 9 is a sectional view taken along line 9-9 of Figure 8;

Figure 10 is a fragmentary sectional view in perspective of an electric lam socket showing the terminal I2 forming the center contact for the lamp base;

Figures 11, 12 and 13 show respectively in plan, side elevation and end elevation another strip of banding connectors embodying my broader invention;

Figure 14 shows in perspective such a con nector applied to a condenser for connecting a lead to a circuit wire;

Figures 15 and 16 show, in side elevation and plan, another embodiment of the invention;

Figure 17 is a top plan view of a resistor coil emtllaodying the connectors of Figures 15 and 16; an

Figure 18-is a cross section taken on line I 8-I 8 of Figure 17.

As shown in Figures 1 to 4, a group of terminals, generally indicated at I2, are arranged in the form of a continuous strip, generally indicated at I3, which comprises a base portion I4 having ears I6 extending upwardly at regularly spaced positions along opposite sides thereof. The ears I6 are arranged in pairs so that each of the ears on one side of the base I4 is positioned directly opposite an ear on the other side of the base. The upper edges of the bars I6 advantageously are swaged to form knife-like edges, as at IT, for reasons that will become apparent later in the description.

A series of fins I8 are spaced along opposite sides of the strip, each fin I8 extending outwardly from and being supported by one of the ears I6, these fins also being positioned in pairs opposite one another along the terminal strip.

The ears I6 may be bent upwardly from the base portion I 4 so that they are approximately perpendicular to the base, or they may form an angle somewhat less than as shown in Figure 4. The outwardly extending fins I8 also can be arranged perpendicularly to the plane of the ears I6, or they may form an angle slightly less than 90 therewith, as shown in Figure 2.

The assembly of a terminal I2, from the strip I3, with a wire, or an insulated conductor from which the insulation has been removed near its end, can be accomplished in a single operation by automatic machinery, but will be described as a series of separate steps in order to simplify the explanation.

A terminal I2 is severed from the strip I 3, as by shearing along the line 22 of Figure 2. This terminal comprises the base I4, the two upright spaced opposed ears I6, the two outwardly-extending fins I8, and a forwardly-extending tongue 24 (see Figures 1 and 2) which is an extension of the base I4. The tongue 24 is then bent downwardly substantially perpendicularly to the base I4 so as to form an additional fin in approximately the same plane as the two side fins I8 (see Figure 4).

This terminal I2 is assembled with an insulated conductor, generally indicated at 26, (Figures 6 to 9) having an inner stranded wire conductor 28 and an outer insulating sheath 32 in the following manner: The wire 28 is exposed for a short distance near the end of the conductor by removing a portion of the insulation sheath 32, and this exposed portion of the wire 28 is placed in the channel formed by the base I 4 and the ears I6 (see Figure 6) with the end of the wire 28 flush with or extending slightly beyond the fins I8 and 24.

The terminal I2 is crimped to the wire 28 by means of a suitable die (not shown), for example, generally similar to the one described in an application of James C. Macy, Serial No. 717,842, filed December 23, 1946, or in the application of Frank L. Pierce, Serial No. 10,951, filed February 26, 1948. By this means, the upper edges of the ears l6 are curved inwardly over the wire 28 and driven downwardly together between the strands of the wire, as shown in Figures 5, 7, 8 and 9, to form the wire-engaging ferrule 30. In some instances, the ears It may not penetrate the conductor, but be driven firmly downwardly on top of the wire or curled outwardly to press the face of its curl against the surface of the wire conductor.

During the initial crimping movement of the upper edges of the ears IS, the inner corners of the fins I8 are forced together, so that the three fins I8 and 24 appear as a block Y (see Figure 7). Further downward movement of the thin edges I! of the ears IE may shear or tear them from the adjacent fins l8 for a short distance near the upper edges of the ears I6, as at 33 in Figure 8 if the end of the die is sharp, or the die may be rounded at its end to form a groined arch in this area in accordance with the copending application Serial No. 10,951, filed February 26, 1948. For some applications it may be desirable to avoid this shearing action by prevent any shearing action A Q In] the" assembled terminal the three finsj I 8 v and 24" form a relatively" larg surface against which a pressure electrical "contact bemad'ef Moreover; the'wirehonductor itself can be allowed toextend at -least flush with o slightly beyond theplane of the three fins so that electrical contactcan be""cbinpleted directly from the wird'itself to the abuttingicontact member.

l lfiesmall angle of fins l8 from theplane normal to'tlie axis of .the strip can be"u"sed' t'o give 'th'is effect. If the wireis insertedtllrough the channel" between sides l'fi until it -abuts'i a stofibey'ond the ends of th fins"l'8, it will th'lis project? beyond the bases of said ears? n the 'ferrule' is crimped onto the wire both it aifd the ire are extruded axial-1y: (du'e to rad coinpressio'n) and this can be utilized to prss me fins l8 against-an-abutment-to bring them into co-planar relation. If it recessed to have the central E conductor project to assure direct" contact," the abutment may terms-sea at the-point where the wire projects at the completion of the crimping operation.

Although a convenient sequence of steps in the application of the connector to the wire is given above, it is not an essential. The connector can be crimped on to the wire before it is severed from the strip and the tongue 24 can be bent down before or after the crimping, to illustrate but a few of the possible variations.

As pointed out above, the terminals can be fabricated from flat sheets of metal without punching out or wasting any of the metal. For example, Figure 5 shows how the connectors of Figures 1-4 can be made from a stock metal strip 34 by shearing along the L-shaped lines 36 (indicated by solid lines) and bendin the sides of the strip 34 upwardly along the broken lines 21. The fins l8 are bent outwardly along the broken lines 38.

Figure 10 shows the end of the terminal l2 mounted in an electric lamp socket 42 to form the center contact thereof. The crimped ferrule It is received in a hole in the insulatin washer 43; the exposed fins l8 and 24 engage the face of the washer in position to make contact with the center contact of the lamp, and the terminal I2 is assembled with the wire 32 connecting the lamp into its circuit (not shown).

From the foregoing it will be observed that the terminal embodying my invention is well adapted for the attainment of the ends and objects hereinbefore set forth and to be economi cally manufactured since waste material is eliminated and its fabrication is achieved by simple cutting and bending operations.

Although the terminal embodying the invention has been described as a center contact for an electric lamp, it should be understood that the invention is not necessarily limited to the use of the terminal in any particular combination; but that many possible embodiments may be made of the invention and many changes from the embodiment set forth, without departing from the scope of the invention.

Examples of such other embodiments are shown in Figures 11 to 18. That of Figures 11 to 14 consists of a simple strip metal bent to channel form with the sides slit at regular intervals and the resulting segments or side portions I641. twisted to a skewed position, shown iii 11'' so" that'the'" opposite" edges:- IBafalie exposed for engagement by'a' fe'edlh :1 pawl or" other r'r'i'echa'n'isIn for precise feeding and positioning, v

Thisstrip" l3d of'Figu're's 11-13 'is" 'particu1arly-' adapted" for application as banding ferru es: Thusi'n Figure 14' a condenser 45 has a lead 46" therefrom connected'to' a wire"'26a by'the crimped'ferrule' band and:

The" example shown in Figures 15-18 can be fed 'either" by a pawl, etcL, engaging 'the' notched edges 48 atthe top of the opposite side's" 16'6" ofb'y' a laterally engaging pawl or' pawls'; etcl', en: gaging" the projectingedg's' [8b. In this'c'ase" these edges'arebentbut just'far'enough to1p'ro-' videsu'ch engagement. The opposite" slits'at these edges IBUar'e'in this case'carried pa'r't" way acrbss the" base Mb, as shown at 50, to" facilitate the" final severance of the in'dividu'al connectors and to" minimize any resulting burr: To the: same end a recess" in the crimpingfdie' may relievthe pressure on thesevered partat" the end or'base [41); as shown at 52 on Fig? are- 18. V H

This is particularly important in the applica--'" tion shown, 1. e., small resistors and coils for electronic circuits, wherein a burr might cause a rupture of the wire in the part of the coil which should make contact. Such a resistor as shown in Figures 17 and 18 consists of a fine wire 54 wound on a core 56 of insulating material tough enough (i. e. resistant and advantageously somewhat resilient to deformation by compression) to form a core against which the wire can be securely engaged by crimping of a ferrule 30b. The contact between the wire coil 54 and the banding ferrule occurs at the side edges 58. On top, as shown in Figure 1'7, the edge recedes because of the tapered ends produced by the notching of the strip, while on the bottom the relieved area 52 avoids contact. The side edges are precisely located by the feed and thus the effective length of the coil is precisely predetermined.

As shown in Figure 18, the two ears Hib of the channel blank are bent over the top of the resistor to close the ferrule, the one ear being bent down fiat and the other being curled down over the wire 28b and the pigtail connection and is compressed with inelastic cold forging of both the ear I 61) and the wire 28b to give a tight rigidly held connection. The other ear lies substantially flat over the top of the coil, being pressed against it and locked by the other, curled end; and this pressure in turn maintains a perfect contact with the coil 54 and with the wire 28b.

Each of these examples, it will be observed, has a succession of connectors partially severed, by shearing or otherwise slitting, at opposite sides of a channel formed of a metal strip, but without removing metal of the strip to space said connectors. As shown each also has a portion of the side bent to expose an edge which can be engaged for feeding and/or positioning the connectors successively with the crimping die.

I claim:

1. An integrally-formed strip composed of a succession of integrally joined terminals for electrical conductors and the like, together comprising a channel-like strip having a continuous base portion, a plurality of substantially identical and contiguous side portions extending at an angle from each side of said base, and each of said side portions being severed from the corresponding side portion of the next terminal and having at least one of the severed edges displaced laterally from the next to provide a strip feeding surface for said formed strip.

2. An electrical connector strip adapted to be parted into individual connectors for use on electrical conductors composed of a succession of integrally joined terminals together comprising a channel-like strip having a continuous base portion, a plurality of substantially identical and contiguous side portions extending upwardly from each side of said base and each of said side portions being severed from the corresponding side portion of the next terminal and having at least one of the severed edges of said side portions displaced outwardly from the next to provide a strip feeding surface for said formed strip.

3. An integrally formed connector strip composed of a succession of integrally joined connectors adapted to be cut into individual connectors for use on electrical conductors and the like together comprising a channel-like strip having a continuous base portion; a plurality of pairs of laterally opposed side portions integrally extending upwardly from said base; said side portions being substantially in edge to edge abutment along their upwardly directed edges; and

8 at least two of said upwardly directed edges of each pair of side portions being laterally displaced from the next adjacent upwardly extending edge portions.

4. A strip as defined in claim 2 wherein said entire side portions are disposed at an angle to the longitudinal axis of said strip.

QUENTIN BERG.

References Cited in the file of this patent UNITED STATES PATEN'I'Sv Number Name Date 1,198,074 Sines Sept. 12, 1916 1,762,848 Whisler -1 June 10, 1930 1,830,084 Bjorndal Nov. 3, 1931 2,142,818 Jacobson Jan. 3, 1939 2,206,662 Conradi et al. July 2, 1940 2,273,099 Gilbert Feb. 17, 1942 2,288,918 Parker July 7, 1942 2,483,424 Martines Oct. 4, 1949 2,558,052 Kumpp, Jr June 26, 1951 FOREIGN PATENTS Number Country Date 346,008 Great Britain Apr. 1, 1931 

